This invention relates generally to transmission of broadband RF communications signals and DC electrical power through a dielectric such as glass. More particularly, this invention relates to transmission of video signals from satellite antenna electronics through a glass window into a structure such as a home, office building or other structure and transmission of driving power from inside the building through the glass to the antenna electronics.
The prior art includes several systems for transmitting single frequency or narrow band RF signals from a mobile telephone antenna through an automobile glass window. Some mobile telephone systems use capacitor plates formed on opposite sides of the glass to transmit the antenna output to a receiver. Other mobile telephone systems use a first slot antenna to radiate the telephone signals across the glass and a second slot antenna to receive the signals and direct them to the receiver. A mobile telephone system is designed to operate at a particular carrier frequency.
Satellite TV systems provide video signals from electronics associated with the antenna to a receiver that is typically located in structure such as a residence, office building or a motor vehicle. The video signals are carried by 75 .OMEGA. coaxial cable. Electrical power for the satellite electronics is provided from the receiver on the same coaxial cable. Installation of a satellite TV system thus requires the delivery of RF signals from the antenna electronics outside the building to a receiver inside the building and the delivery of electrical power from the receiver to the antenna electronics. Typical installations require drilling a hole through a wall or window frame to provide a passage for the coaxial cable.
In many cases drilling a hole through a wall of a structure is undesirable. Many home owners do not want holes drilled through their walls. In rental residential or commercial property drilling a hole through a wall may be impermissible. In many cases drilling a hole in a wall of a motor vehicle is unacceptable to the owner or user of the vehicle.
The mobile telephone systems, being single frequency or narrow band cannot be adapted for video signals, which cover a frequency range of about 900 MHz to 1500 MHz. The mobile telephone systems are directed to connecting a receiver and an antenna without regard to potential common mode interference problems that arise from other radiating sources. In a satellite TV system the problem is electrically coupling the receiver and a transmission line, which is connected to the output of the electronics, typically a preamplifier, that the antenna manufacturer has included with the antenna. The mobile telephone systems also do not provide power from the receiver to a preamplifier that is outside the vehicle.
Therefore, there is a need in the art for a system for installing a satellite TV system without drilling a hole through the structure where the satellite TV system is being installed.